June 6, 2018

Population Structure and Threats to Sustainable Management of Woody Plant Species in a Semi-Arid Agro-Ecosystem in Nigeria || JBES V.8-N.2

By: T.H. Dauda, S.O. Jimoh, I.O. Azeez

This study was conducted to assess population structure and threat to the sustainable management of woody species in the various ago-ecosystems in Dutsin-Ma Local Government Area (LGA) Katsina State, Nigeria. Purposive and stratified random sampling techniques were used to collect data from 21 randomly demarcated 100m × 100m sample plots. All woody plant species found in the sample plots with stem diameter >2 cm at 20cm above ground, were recorded. Population structure was summarized by diameter classes. For the identification of threats, field and questionnaire surveys were used. A total of 50 questionnaires were distributed at ten questionnaires per ward in five out of the 11 wards in the LGA.

The highest numbers (350) of small diameter trees (0.1-1.0cm) were recorded in the agrosilvopastoral system. This was followed by silvopastoral and agrisilviculture systems with 89 and 85, respectively. However, the highest number of large diameter woody tree species was recorded in the silvopastoral system followed by agrosilvopastoral and agrisilviculture systems. The regular reverse J-shaped and fairly regular reverse J-shaped size class distribution observed for agrosilvopastoral and silvopastoral respectively, suggest a recuperating population. Over exploitation, debarking, de-branching, root- digging, leaf harvesting, seed harvesting, poor regeneration, slow rate of growth, wind effect and bush burning were the major threats to sustainable management of woody plant species in the study area. The implications of our findings for sustainable management of woody plant species in the study area are discussed and recommendations are made.


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The flame temperature effect on the reduction of environmental pollutants in a thermal power plant

Get the full abstract and pdf articles at J. Bio. Env. Sci. 8(2), 275-282, February 2016.



June 3, 2018

Carbon dioxide and energy fluxes above an oil palm canopy in peninsular Malaysia || IJAAR - V9N2-P137-46


By: MH Haniff, Anis Ibrahim, Nur Maisarah Jantan, Nuramanina Shahabudin, Hasimah Mos, Yusri Yusup

A study was conducted on carbon dioxide (CO2) and energy fluxes (i.e. latent (L) and sensible heat (H)) above the canopy of mature oil palms planted on the inland mineral soil in Keratong, Pahang, Peninsular Malaysia. The measurement was conducted over an 18-month period from September 2013 to August 2014, using the eddy covariance method. There was a significant seasonal variation in the monthly averaged CO2 fluxes over the measurement period. The monthly averaged CO2 flux values ranged between -2 to -6 μmol m–2 s–1, with an average value of about -3.5 μmol CO2 m–2 s–1. This could be due to the irregular cumulative monthly precipitation and net radiation during the observation period. Relatively low average monthly CO2 flux (or high uptake of CO2) also corresponds with the lowest monthly average LE and rainfall in months February 2013 and 2014. The negative CO2 flux value shows that the mature oil palm ecosystem from an inland mineral soil area in Peninsular Malaysia was a sink for CO2. Analysis of energy balance closure shows that the slope between latent and sensible heat fluxes and total incoming energy was about 0.69 with an r2 value of 0.86. The slope value obtained in this study suggests that there was a surplus of available energy compared to the measured energy fluxes. Energy balance ratio was about 0.81 and comparable to other agricultural surfaces. This means that 81% of the available energy was accounted through the surface flux measurements.
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Get the full articles at Carbon dioxide and energy fluxes above an oil palm canopy